The present invention relates to devices for releasably closing cartons and boxes.
The conventional corrugated cardboard carton or box typically has four top flaps, one extending from each of four side walls. The outer top flaps overlie the inner top flaps, forming a double thickness of corrugated material. An effective closure or seal can be ensured by applying strapping tape, staples, or the like. The carton may also be closed by interleaving the top flaps one with other, although this method of closure will tend to distort the box flaps and is not always satisfactory. In my U.S. Pat. No. 3,545,801, entitled “Box Closure Fastening”, the disclosure of which is incorporated by reference herein, I disclosed a molded plastic box closure which had a half-disc-shaped upper member connected by a stem to a lower disc. The stem spaced the upper member from the lower disc such that the four box flaps could be received between the upper and lower members, thereby holding the box closed. The half-disc-shaped upper member allowed the closure to be rotated in 90 degree increments to stepwise engage each of the four flaps. This device provided a convenient reusable closure for cartons, and further disclosed a rigid protruding carrying handle, which aided in carrying of the box and the rotating of the device into engagement with the box flaps.
Although an upwardly protruding handle provides leverage in rotating the device, the vertical protrusion can interfere with stable stacking of multiple closed cartons, yet without such a handle, the narrow discs can be challenging to conveniently install and manipulate. What is needed is a low-profile, user-friendly, and conveniently installable box closure which will not interfere with or preclude the stacking of one closed box upon another yet will also provide, if desired, a handle to carry the closed box.